import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.*;

public class TestMain {
    public static void main(String[] args) {
        try {
            FileInputStream fileIn= new FileInputStream("aaa.txt");
            byte[] a= new byte[1024];

            int i= fileIn.read(a);
            System.out.println("文件输入流返回值："+i);
            FileOutputStream fileOut = new FileOutputStream("bbb.txt");
            fileOut.write(a);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
